The History of Dental Amalgams
This is the first in a series of three articles about dental amalgams. In this article, we’ll focus on the history of dental amalgams – and how modern-day versions barely resemble what was used in ancient China.
Li Yuan had a toothache.
As Emperor Gaozu of the Tang Dynasty in 618 AD, Li Yuan belonged to a military aristocracy which gave him power and prestige. But even his power couldn’t guarantee him freedom from tooth decay and painful toothaches. Li Yuan consulted with his ‘tooth doctor’, seeking relief. The early dentist recommended extraction, which had been common in China since 7000 BC. But he had been experimenting with melted silver and tin, which he packed into the rotted areas of teeth. This would allow Li Yuan to avoid losing his tooth and still chew his food, while hopefully alleviating the toothache.
Of course, we have no way of knowing if this really happened to Li Yuang, or if it would have provided much relief from his toothache. We can surmise that people must have been pretty desperate to undergo extractions and other procedures without pain blockers.
The first known dental amalgams were used during the Tang Dynasty, made from tin and silver according to medical texts written by Su Kung in 659 AD. The Chinese were experts in dentistry by the time Li Yuan became Emperor, though. They had been practicing dentistry since 7000 BC, using wires to stabilize teeth and performing routine extractions.
Amalgams evolved over the years, as more stable materials were discovered. In 1505, Liu Wen Taiin wrote about using “100 shares of mercury, 45 shares of silver, and 900 shares of tin” to fill teeth. The addition of mercury to silver and tin made the material easier to form and better at filling in crevices.
If you lived in France and had cavities in the early 1700’s, your teeth might have been filled with lead, tin and gold. Pierre Fauchard, often called the ‘Father of Modern Dentistry’ wrote ‘The Surgeon Dentist’ in 1728, extolling the benefits of proper dental hygiene, restorative dentistry and even early orthodontics. (You may also thank him for inventing the dental drill) He used lead because it rendered the other metals more malleable, making it more easily fit into a tooth. Lead wore down quickly, however, which meant that the fillings didn’t last very long. Later, when the toxicity of lead was discovered, it was abandoned as a material used for restorative dentistry.
Modern amalgams were introduced in the Western world during the early 1800’s. French Dentist Auguste Taveau developed a dental amalgam in 1816 which contained a small amount of mercury and melted silver coins. In 1826, Taveau used the material as a dental restorative and filler. The mixture had some practical issues, because it tended to expand significantly after setting. However, mercury was soft enough to mold to a tooth, and after curing lasted a long time.
Edward Crawcour and his nephew Moses brought amalgam to the United States in 1833. The two came to New York from England, introducing a new method for using amalgams to fill the teeth of dental patients. According to the New Hampshire Patriot in an 1835 article, the two soon had warrants for their arrest based on complaints for poor dentistry.
They supposedly earned over $60,000 in just 12 weeks (the equivalent of $1,600,000 in today’s dollars). This apparently incensed a group of New York dentists who executed a plan for one of them to receive a filling from the Crawcours. They then removed the filling and had it tested by a chemist. Upon finding that hydrargyrum, then called ‘quicksilver’, was among the ingredients, they rallied to have the Crawcours arrested. (By then the Crawcours had set sail on the ship ‘Napolean’, returning to England and evading incarceration.) At the time of their rapid departure, it is estimated that the Crawcours had filled the teeth of almost half the adults in New York.
Interestingly, many dentists were already defending the use of mercury (hydrargyrum) as a superior material for filling dental caries. These early amalgams contained tin, silver, copper, zinc and mercury. Gold was popular, but it was also far more expensive and much more difficult to place in a tooth than the ‘newer’ amalgams.
Although the proportions of the metals have changed since 1835, dental amalgams are still primarily made from a combination of silver, tin, copper, zinc and mercury.
Next in this series on Amalgams: How and when dental amalgam fillings are used, their safety and longevity.